Print: | ISSN 0304-128X |
Online: | ISSN 2233-9558 |
HWAHAK KONGHAK,
Vol.41, No.2, 224-231, 2003 산소플라즈마처리를 통한 PAA-grafted PU 필름 합성에 대한 온도의 영향
Effect of Reaction Temperature on the Synthesis of PAA-grafted PU Films through an Oxygen Plasma Treatment
Toluene 2,4-diisocyanate(TDI)와 polyol을 사용하여 Polyurethane(PU) 필름을 합성하였고, 산소플라즈마 처리를 통하여 이 폴리우레탄 필름에 peroxide를 도입한 후, peroxide를 개시제로 한 용액반응으로 Polyacrylacid(PAA)-grafted PU 필름을 합성하였다. 1,1-diphenyl-2-picrylhydrazyl(DPPH)법으로 알아낸 폴리우레탄 표면에 생성된 peroxide의 최대 농도는 2.0 nmol/cm(2)이었으며, 용액 반응온도에 따른 그래프팅도의 변화를 조사하였다. PAA-grafted PU 필름의 표면 분석은 ATR-IR과 ESCA를 이용하였고, 도입된 -COOH의 정량분석은 역적정법을 이용하였다. 본 연구의 결과, 그래프트된 폴리우레탄 필름의 관능기는 반응 온도가 증가함에 따라서 증가하였으며, 이로부터 계산된 겉보기 활성화에너지는 Ea=39.5 kJ/mol이었다. 본 결과를 타 연구결과와 비교 분석한 결과 반응의 활성화에너지는 기재의 종류 및 구조에 크게 의존함을 알 수 있었다. 끝으로, ESCA 및 SEM을 통하여 합성된 PAA-grafted PU 필름의 구조 분석 결과, PU 표면에 형성된 PAA는 지역적으로 불균일한 분포를 보여주었다.
Polyurethane (PU) films were synthesized from toluene 2,4-diisocyanate (TDI) and polyol. After introducing peroxides on the PU films through oxygen plasma treatment, PAA-grafted PU films were synthesized through the solution reaction of acrylic acid monomer with peroxides which are used as initiators. The maximum concentration of peroxides obtained by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method was 2.0 nmol/cm(2) and we investigated the effect of reaction temperature on the change of grafting degree. The surface properties of the surface-modified PU films were characterized by the Attenuated Total Reflection-Fourier Transformed Infrared (ATR-FTIR) and Electron Spectroscopy for Chemical Analysis (ESCA). We measured the quantity of introduced -COOH groups using back-titration method. As results of this study, the amount of PAA grafted on PU film was increased with increasing reaction temperature and the apparent activation energy of this reaction was 39.5 kJ/mol. After comparing this result with other previous results, we could conclude that the activation energy of this reaction strongly depended on the type and the structure of substrate materials. Finally, since the dried PAA-grafted PU film showed locally-agglomerated non-uniform structure as the result of observations through ESCA and SEM, the PAA chain grafted on PU film certainly had locally different lengths due to the complex reaction paths.
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